picker组件在data数组为[[]]时点击确定无法关闭弹窗

### Version
1.12.24

### Reproduction link
[https://rusrn.codesandbox.io/](https://rusrn.codesandbox.io/)

### Steps to reproduce
picker组件在data数组为[[]]时点击确定无法关闭弹窗
初始化后第一次可以正常关闭 之后就无法通过确定关闭

### What is expected?
当picker组件在data数组为[[]]时点击确定也能正常关闭

### What is actually happening?
picker组件在data数组为[[]]时点击确定无法关闭picker

### Dependencies Version
vue: 2.6.9
better-scroll: 1.15.0